In the js-php method, the for loop length is 0.

I am doing a datagrid deletion function. when I select all, I get the id of the selected row and use ajax to jump to the self-written SQL method, such as LY. ajax. request ({urlsql path surress: function () {}, parems: function () {act: SQL statement did: 12,4, 5, id }}) in the SQL method, accept $ did $ _ POST [& #39; did & #39;]; and then use for ($ i0; count ($ did); $ ++) {$ dd & quot; where10or jsphp

I am doing a datagrid deletion function. when I select all, I get the id of the selected row and use ajax to jump to the self-written SQL method, for example, LY. Ajax. request ({
Url SQL path
Surress: function (){
}, Parems: function (){
Act: SQL statement
Did: 12, 4, 5, id
}
})
In the SQL method, accept $ did =$ _ POST ['did'];
Then use for ($ I = 0; count ($ did); $ ++ ){
$ Dd = "where 1 = 0 or id = $ did [$ I]"
} In this way, no data can be written cyclically. I want to use a statement to delete multiple rows based on the ID, but I cannot read them cyclically. how can this problem be solved?